1. Field of the Invention
This invention broadly relates to orthodontic appliances and adhesive materials that are used in the patient's oral cavity during the course of orthodontic treatment. More particularly, the present invention is directed to a packaged assembly that includes at least one orthodontic appliance and a quantity of adhesive material for application to the base of each appliance.
2. Description of the Related Art
Orthodontic treatment involves movement of malpositioned teeth to orthodontically correct positions. Tiny orthodontic appliances known as brackets are connected to exterior surfaces of the patient's teeth, and an archwire is placed in a slot of each bracket. The archwire forms a track to guide movement of the teeth to desired positions for correct occlusion. End sections of the archwire are often received in appliances known as buccal tubes that are fixed to the patient's molar teeth.
In recent years it has become common practice to use adhesives to bond orthodontic appliances to the surface of the tooth, using either direct or indirect methods. Orthodontic adhesive is often applied to the base of the appliance by the practitioner immediately before the appliance is placed on the tooth. In some instances, a quantity of adhesive is dispensed onto a mixing pad or dispensing well, and a small spatula or other hand instrument is then used to apply a small dab of adhesive to each appliance. In other instances, a quantity of adhesive is dispensed from a syringe directly onto the base of the appliance.
Adhesive precoated brackets are known and offer significant advantages to the orthodontist. Adhesive precoated brackets have a bonding base upon which the manufacturer may apply a precise quantity of adhesive such as a photocurable adhesive. In direct bonding methods, when it is desired to mount the bracket on a tooth, the bracket is simply removed from the package and placed directly onto the tooth. For indirect bonding methods, brackets are removed from the package and placed, for example, on a replica plaster or “stone” model of the patient's dental arch to provide a custom base for later mounting on the patient's tooth, commonly using a transfer tray or indirect bonding tray.
Adhesive precoated orthodontic appliances are often packaged in containers that protect the adhesive from light, moisture and contaminates. Known containers include containers that receive only a single appliance. The adhesive is coated by the manufacturer onto the base of the appliance and rests on a release surface within the container. The release surface has properties that facilitate disengagement from the adhesive when the appliance is lifted from the container without unduly disturbing the overall shape of the adhesive.
A wide variety of orthodontic adhesives are available, and some practitioners prefer to use orthodontic adhesives with relatively low viscosities. However, low viscosity adhesives pose difficulties when precoated onto the base of appliances by the manufacturer. For example, the adhesive may not be sufficiently stiff to prevent the bracket from shifting on the release surface in the package and deforming the shape of the adhesive.
In addition, efforts have long been underway to develop new orthodontic adhesives with improved functional properties. Examples of such properties include sustained fluoride release and moisture tolerance. As can be appreciated, it would be a significant advantage to provide a packaging construction for precoated appliances that can be used with a number of different adhesive materials.